Doha: Allyson Felix won her 12th world title, and her first since becoming a mother, as the United States claimed the inaugural world championship 4x400 metres mixed relay on Sunday.
In doing so, Felix, who won her first gold in 2005, overhauled Usain Bolt's record of 11 world titles.
Felix ran the second leg as the US team also featuring Wilbert London, Courtney Okolo and Michael Cherry won in three minutes 9.04 seconds -- a world record for the new event -- to finish ahead of Jamaica and Bahrain.
The team draped themselves in US flags as they celebrated their win but, with barely any spectators in the Khalifa Stadium, went straight down the tunnel instead of completing a lap of honour.
Seven of the eight teams chose to run the first and fourth legs with men while Poland went for men in the first two legs and women in the last two.
That meant the Poles finished the second leg with a healthy lead which was cut back in the third leg and obliterated within the first 100 metres of the fourth as Justyna Swiety-Ersetic was overtaken by Cherry. Poland eventually finished fifth.
Felix, 33, has also won three world titles in the women's 200 metres, one in the 400 metres, three in the women's 4x100 metres relay and four in the women's 4x400 metres relay.
India finish seventh
The Indian mixed 4x400m relay team finished seventh.
The quartet of Muhammed Anas, V K Vismaya, Jisna Mathew and Tom Nirmal Noah had qualified for the 2020 Tokyo Olympics after reaching the finals on Saturday.
